Counterbalance for the crank shafts of internal-combustion engines



F. 0. STERRETT.

COUNTERBALANCE FOR THE CRANK SHAFTS OF INTERNAL COMBUSTION ENGINES.

A PPLCAT!0N FILED AUG-H, 1921.

Patented. July 111, 1922.,

GQUNT a:

To all whom it inaycomem. I

Be it known that I, FRANK O. STERRETT, a citizen of the United States, residing at Rochester, county of Pershing, State of Neva'da, have invented certain new and useful Improvements in Counterbalances for the Crank Shafts of Internal-Combustion Engines, of which the following is a specificat1on.,. Y

In the constrne'iion of certain types of internal combustion engines, and more particularly that known as the four-cylinder type, it is-the practice to dispose the cranks for the several cylinders oppositely to each other, or in words, 180 apart. An internal combustion' engine differs in operation from other forms of engines, such as steam engines, in that the motive force is imparted in the form of a blow, the power is generated series of explosions in the various cylinders. This operation exerts a percussive force upon the crank shaft, and while it has been the due to the fact that practice, particularly in automobile four-.

cylinder engines, such as that of the Ford type, to provide a fly wheel fixed to the crank shaft, still no provision has been made for 7 .being had to counter-balancing the shaft in opposition to the percussive blows imparted by the series of explosions.

My present invention is desi ed to obviate this defect and to provide t e fly wheel of such an engine with counter-Wei hts disposed with respect to the cranks of t e crank shaft so that a scientific counter-balancing will be effected. This object I accomplish by disposing upon the fly wheel two counterweights 180 apart and 90 from the angle of the cranks.

My invention embodies certain minor novel features of construction, as hereinafter will be pointed out and claimed, reference the accompanying drawing, in which:- I

Figure 1 is a view partly in vertical section, and partly in diagrammatic elevation of the casing, crank shaft and fly wheel of a. Ford four-cylinder motor.

Figure 2 is an enlarged detail sectional view of the fly wheel.

Figure 3 is a side elevation of and crank shaft.

' Similar numerals of reference denote corresponding parts in theseveral views.

In the said drawing, the reference numeral 1 denotes the motor casing of a Ford the fly wheel Specification of Letters Patent.

, nets 6 are secured on the instantaneously by a ALANCE FOB T CRANK SHAFTS 0F INTERNAL-GOMBUSTION ENGINES.

Patented July ii, 11922.

Application filed August 11, 1921. Serial No. 491,630.

motor, in Which is mounted in the usual manner the crank shaft 2 having the cranks 3 formed thereon 180 apart, as shown, said cranks having attached thereto the usual connecting rods i connected to the cylinder pistons (not shown). Fixed to said crank shaft in the usual manner is the fly wheel 5. A seriesof V-shaped permanent field-magfly wheel adjacent the crank casing with their arms in substantially radial position. Said magnets are disposed preferably in pairs, the positive poles of each pair being adjacent and are insulated magnetically each from the other by air gaps. Their inner neutral portions at the bends are held rigid by suitable means, as. by bolts 7 against an annular shoulder concentric on the fly wheel near its hub. The

outer ends of the arms of the adjacent field magnets ti are secured by magnetic fastenings, such as clips 8 through which capscrews 11 are passed into the fly Wheel. The face of the fly wheel being dished or recessed annularly near its outer periphery, a space is afl'orded between said fly wheeland the ends of the arms of the field magnets 65, and in this space, and oppositely disposed with respect to each other, I insert two counterweights 9, segmentally shaped to correspond with the periphery of the fly wheel, said counter-weights being retained in position by screw-bolts 10, and also by the cap-screws 11, which position the clips 8.

By reference to Figures 1 and 3, it will be seen that said counter-weights 9*are disposed upon the fly wheel 5 with respect to the cranks 3 so that they lie 90 from" said cranks] Now, in the operation of the motor the power stroke is imparted to each crank at approximately the moment when it reaches its upward limit of movement, and at this moment the counter-weights 9 will be disposed upon opposite .sides of the crank shaft 90 from the point of application of the power blow, which position has been found in practice to result in a material deproviding. in the fly wheel for the reception of the retaining screw bolts 10.

Havin thus fully described my invention, what I claim as new and desire to secure by Letters Patent, is 2-,-

1.. The combination with the crank shaft of a multi-cylinder internal combustion engine having its cranks disposed in the same plane, and a fly wheel ,mounted. thereon, said fly wheel being counter-weighted in such manner that the counter-weighted portions are disposed thereon with respect to said-cranks at substantially 90 intervals.

. 2. The combination with the crank shaft.

of a multicylinder internal combustion engine having its cranks disposed in the same plane, and a fly wheel mounted thereon, of

counter-weights fixed to said fly wheel and disposed thereon with respect to said cranks at 90 intervais.

- 3. The combination with the crank shaft of a multi-cylinder internal combustion engine having its cranks disposed in the same plane, and a fly wheel mounted thereon, of counter-Weights detachably fixed to one face of said fly Wheel and disposed thereon with respect to said cranks at 90 intervals.

4. The combination with the crank shaft of a multi-cylinder internal combustion engine haying its cranks disposed in thesame plane, a fly wheel mounted thereon, and a series of V-shaped permanent field magnets secured on one face of said fly wheel with their arms in substantial radial position, of counter-weights fixed to said face of the fly wheel beneath said magnets and disposed thereon with respect to said cranks at 90 intervals.

In testimony whereof I hereunto afix my signature.

FRANK O. STERRETT. 

